Total fat and omega-3 fatty acids intake in relation to serum brain-derived neurotrophic factor (BDNF) levels and psychological disorders in Iranian adults

The relationship between different fatty acids intake and the depressive symptoms: A population-based study

BACKGROUND

Depression is a common psychological disorder worldwide, affecting mental and physical health. Previous studies have explored the benefits of polyunsaturated fatty acids (PUFAs) intake in depressive symptoms; however, few studies have focused on the association between all types of fatty acids intake and depressive symptoms. Therefore, we explored the relationship between the intake of different fatty acids intake and the risk of depressive symptoms.

METHODS

The study was based on the data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES), a large US-based database. We used a nutrient residual model and multi-nutrient density model for the analysis. We calculated the nutrient density and residual in men and women separately, and the fatty acids intake was divided into quartiles based on the sex distribution. The relationship between the depressive symptoms and the intake of different fatty acids was examined using logistic regression; furthermore, we explored the relationships separately in men and women.

RESULTS

The intake of monounsaturated fatty acids (MUFAs) and PUFAs, particularly n-3 and n-6 PUFAs, were associated with reduced odds ratios for depressive symptoms. The inverse relationship between the intake of MUFAs, PUFAs, n-3, and n-6 PUFAs and depressive symptoms was stronger in women. The inverse relationship between total fatty acid (TFAs) intake and depressive symptoms existed only in a single model. In contrast, saturated fatty acid (SFAs) intake was not related to depressive symptoms.

CONCLUSION

Consuming MUFAs and PUFAs can counteract the depressive symptoms, especially in women.

A systematic review and meta-analysis of the omega-3 fatty acids effects on brain-derived neurotrophic factor (BDNF)

BACKGROUND

Omega-3 fatty acids (omega-3 FAs) have attracted the attention of researchers because of their influence on circulatory levels of brain-derived neurotrophic factor (BDNF). Our objective was to review systematically and Meta-analyze randomized controlled trials (RCTs) to assess the effects of omega-3 FAs supplementation on serum BDNF concentration.

METHODS

Scopus, PubMed, Web of Science, and Cochrane Library were systematically searched until April 2023. The Cochrane risk of bias assessment tool was utilized to evaluate the quality of the studies. A random-effects model was employed to estimate the overall effect size of BDNF levels, using the Standard Mean Difference (SMD) and a 95% confidence interval (CI). The heterogeneity among the studies was assessed using chi-squared and I2 statistics.

RESULTS

A total of 12 studies involving 587 subjects were included. The supplementation of PUFA was found to be associated with a significant increase in serum levels of BNDF in the group receiving the supplements, as compared to the placebo group (SMD: 0.72 pg/mL, 95% CI: 0.28, 1.15; P < 0.001) (I2 = 84.39%, P < 0.001). Sub-group analyses revealed similar findings in trials with fewer than 10 weeks, which utilized both animal (fish oil) and herbal (flaxseed) forms of omega-3 supplements with a high daily dosage of 2000mg.

CONCLUSION

The present systematic review and meta-analysis indicate the efficacy of omega-3 FAs in increasing the serum concentration of BDNF. Therefore, omega-3 FAs should be prioritized as agents for increasing BDNF in interventions.

Association of macronutrient consumption quality, food source and timing with depression among US adults: A cross-sectional study

BACKGROUND

Growing evidence suggests that meal timing may influence dietary choices and mental health. Thus, this study examined the association between macronutrient consumption quality, food source, meal timing, and depression prevalence in Americans.

METHODS

23,313 National Health and Nutrition Survey participants from 2007 to 2016 were included in this cross-sectional study. Macronutrient intake was calculated for all day, dinner, and breakfast and subtypes into 4 classes. Based on the Patient Health Questionnaire, depression was defined as a 9-item score ≥ 10 on the PHQ-9. The correlation between macronutrients and depression prevalence was estimated with multivariable logistic regression models and isocaloric substitution effects.

RESULTS

Low-quality carbohydrates (OR = 1.54, 95 % CI: 1.11, 2.12) were positively linked to depression compared with the lowest quartile, after adjusting for age and other covariates. In contrast, total high-quality carbohydrate (OR = 0.52, 95 % CI: 0.40, 0.66), total animal protein (OR = 0.60, 95 % CI: 0.45, 0.80), and total vegetable protein (OR = 0.61, 95 % CI: 0.43, 0.85) were negatively associated with depression was negatively associated. Replacing low-quality carbohydrates with high-quality carbohydrates throughout the day reduced the risk of depression by approximately 15 %.

LIMITATIONS

Cross-sectional data.

CONCLUSION

All in all, diet plays a crucial role in the prevention and treatment of depression. Especially in terms of macronutrient intake, high-quality, moderate intake can reduce the risk of depression. However, different subtypes of macronutrient consumption may have different effects on depression, so it becomes crucial to carefully consider the selection and combination of macronutrients.